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Zhang A.-Q.,Zhejiang University of Technology | Fu L.,Zhejiang University of Technology | Xu M.,Zhejiang University of Technology | Sun P.-L.,Zhejiang University of Technology | Zhang J.-S.,Shanghai Academy of Agricultural science
Carbohydrate Polymers | Year: 2012

A new heteropolysaccharide (HEPF4), with a molecular weight of 2.03 × 10 4 Da as determined by high-performance liquid chromatography (HPLC), was obtained from the fruiting bodies of Hericium erinaceus. It is composed of 3-O-methylrhamnose, l-fucose, d-galactose and d-glucose in the ratio of 0.12:1.00:3.27:0.28. Its chemical structure was characterized by sugar and methylation analysis, along with 1H and 13C NMR spectroscopy, including NOESY and HMBC experiments for linkage and sequence analysis. The polysaccharide is composed of a tetrasaccharide repeating unit (described in the results section). HEPF4 also contains a minor proportion of glucose and 3-O-methylrhamnose which is believed to terminate the polymer main chain. © 2011 Elsevier Ltd. All rights reserved. Source

Du X.,Liaocheng University | Mu H.,Liaocheng University | Zhou S.,Shanghai Academy of Agricultural science | Zhang Y.,Liaocheng University | Zhu X.,Liaocheng University
International Journal of Biological Macromolecules | Year: 2013

Three water-soluble polysaccharide fractions (IOP40, IOP60 and IOP80) were isolated by using different concentrations of alcohol precipitation from Inonotus obliquus sclerotia. Their physicochemical properties, including total sugar content, protein content, monosaccharide composition and percentage were analyzed. And their in vitro antioxidant capacities were investigated in terms of reducing power assay and scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals, hydroxyl radicals, superoxide anion radicals and hydrogen peroxide (H2O2). In general, three polysaccharide fractions exhibited increasing antioxidant activity with increasing concentration at the ranges of tested dosage. The orders of reducing power, DPPH-scavenging capacity, H2O2-scavenging capacity, and hydroxyl-scavenging activity were all IOP60>IOP40>IOP80. These findings demonstrated that three polysaccharide fractions extracted from I. obliquus, especially IOP60, could be employed as natural ingredients in functional food and pharmaceutical industry to alleviate the oxidative stress. © 2013 Elsevier B.V. Source

Zhang J.,University of Shanghai for Science and Technology | Zhang J.,Shanghai Academy of Agricultural science
Critical Reviews in Biotechnology | Year: 2015

Filamentous fungi play an important role not only in the bio-manufacturing of value-added products, but also in bioenergy and environmental research. The bioprocess manipulation of filamentous fungi is more difficult than that of other microbial species because of their different pellet morphologies and the presence of tangled mycelia under different cultivation conditions. Fungal pellets, which have the advantages of harvest ease, low fermentation broth viscosity and high yield of some proteins, have been used for a long time. Many attempts have been made to establish the relationship between pellet and product yield using quantitative approaches. Fungal pellet formation is attributed to the combination of electrostatic interactions, hydrophobicity and specific interactions from spore wall components. Electrostatic interactions result from van der Waals forces and negative charge repulsion from carboxyl groups in the spore wall structure. Electrostatic interactions are also affected by counter-ions (cations) and the physiologic conditions of spores that modify the carboxyl groups. Fungal aggregates are promoted by the hydrophobicity generated by hydrophobins, which form a hydrophobic coat that covers the spore. The specific interactions of spore wall components contribute to spore aggregation through salt bridging. A model of spore aggregation was proposed based on these forces. Additionally, some challenges were addressed, including the limitations of research techniques, the quantitative determination of forces and the complex information of biological systems, to clarify the mechanism of fungal pellet formation. © 2015 Taylor & Francis. Source

Zhang L.,Shanghai JiaoTong University | Yu S.,Shanghai Academy of Agricultural science | Zuo K.,Shanghai JiaoTong University | Luo L.,Shanghai Academy of Agricultural science | Tang K.,Shanghai JiaoTong University
PLoS ONE | Year: 2012

Understanding the molecular mechanisms that underlie plant responses to drought stress is challenging due to the complex interplay of numerous different genes. Here, we used network-based gene clustering to uncover the relationships between drought-responsive genes from large microarray datasets. We identified 2,607 rice genes that showed significant changes in gene expression under drought stress; 1,392 genes were highly intercorrelated to form 15 gene modules. These drought-responsive gene modules are biologically plausible, with enrichments for genes in common functional categories, stress response changes, tissue-specific expression and transcription factor binding sites. We observed that a gene module (referred to as module 4) consisting of 134 genes was significantly associated with drought response in both drought-tolerant and drought-sensitive rice varieties. This module is enriched for genes involved in controlling the response of the plant to water and embryonic development, including a heat shock transcription factor as the key regulator in the expression of ABRE-containing genes. These results suggest that module 4 is highly conserved in the ABA-mediated drought response pathway in different rice varieties. Moreover, our study showed that many hub genes clustered in rice chromosomes had significant associations with QTLs for drought stress tolerance. The relationship between hub gene clusters and drought tolerance QTLs may provide a key to understand the genetic basis of drought tolerance in rice. © 2012 Zhang et al. Source

Halford N.G.,Rothamsted Research | Curtis T.Y.,Rothamsted Research | Chen Z.,Shanghai Academy of Agricultural science | Huang J.,Shanghai Academy of Agricultural science
Journal of Experimental Botany | Year: 2015

The effects of abiotic stresses and crop management on cereal grain composition are reviewed, focusing on phytochemicals, vitamins, fibre, protein, free amino acids, sugars, and oils. These effects are discussed in the context of nutritional and processing quality and the potential for formation of processing contaminants, such as acrylamide, furan, hydroxymethylfurfuryl, and trans fatty acids. The implications of climate change for cereal grain quality and food safety are considered. It is concluded that the identification of specific environmental stresses that affect grain composition in ways that have implications for food quality and safety and how these stresses interact with genetic factors and will be affected by climate change needs more investigation. Plant researchers and breeders are encouraged to address the issue of processing contaminants or risk appearing out of touch with major end-users in the food industry, and not to overlook the effects of environmental stresses and crop management on crop composition, quality, and safety as they strive to increase yield. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. Source

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